initialize a 2d array java code example

Example 1: two dimensional array in java example program

class MultidimensionalArray {
    public static void main(String[] args) {

        int[][] a = {
            {1, -2, 3}, 
            {-4, -5, 6, 9}, 
            {7}, 
        };
      
        for (int i = 0; i < a.length; ++i) {
            for(int j = 0; j < a[i].length; ++j) {
                System.out.println(a[i][j]);
            }
        }
    }
}

Example 2: 2d array java

//Length
int[][]arr= new int [filas][columnas];
arr.length=filas;

        int[][] a = {
            {1, 2, 3}, 
            {4, 5, 6, 9}, 
            {7}, 
        };
      
        // calculate the length of each row
        System.out.println("Length of row 1: " + a[0].length);
        System.out.println("Length of row 2: " + a[1].length);
        System.out.println("Length of row 3: " + a[2].length);
    }

Example 3: declare matrix in java

int[][] multi = new int[5][];
multi[0] = new int[10];
multi[1] = new int[10];
multi[2] = new int[10];
multi[3] = new int[10];
multi[4] = new int[10];

Example 4: Java 2d array initialization

class TwoDimensionalArray {

    public static void main(String[] args) {
        String[][] salutation = {
            {"Mr. ", "Mrs. ", "Ms. "},
            {"Kumar"}
        };

        // Mr. Kumar
        System.out.println(salutation[0][0] + salutation[1][0]);

        // Mrs. Kumar
        System.out.println(salutation[0][1] + salutation[1][0]);
    }
}

The output from this program is:

Mr. Kumar
Mrs. Kumar

Example 5: how to initialize one dimensional array in java

int[] a; // valid declaration
int b[]; // valid declaration 
int[] c; // valid declaration